Pilot for furnaces



Dec. 2, 1930.

O. H. RODENBERG PILOT FOR FURNACES Filed July 15, L929 I l l huun I l II II x.

I N VEN TOR.

A TTORNEYS Patented Dec. 2, 1930 PATENT? OFFICE} I l o'r'ro n.'RODENBERG, F cmo nivnrr, oHIo rrnozr roR summons n pncationn a July15,1929; serial no. 378,326; r g

' My invention relates to pilots for gas fired furnaces and oil burningfurnaces, and particularly to'gas pilots provided with an automaticcontrol for'governing the operation of the pilot.

In theart the use of pilots disclosing the general combination ofelements involved'in the particular type of pilot topwhich my inventionrelates 'has been quite extensively de-" veloped." The construction ofsuch pilots is broadly as follows There is an outer "shell within which'an expansion tube is mounted.

The expansion tube is secured to' the outer shell adjacent the end ofthe shell at afiposition in which aibran'ch extends at an. angleto' thetube and from the end of the branch pipefthe gas flows in a stream tocause the ignition of the gas or oil in'the main burners in the furnace.There are a series of small orifices in the tube. in an exposed portionthereof adjacent the branch discharge pipe and a series of jets of gtsburning from these orifices causes the tube to expand and, being fixedat one end, the tubeexpands through the outerend of the shell where itcontrols an electric switch which inturn' governs a gas supply valve.

In pilots of the type described, if the branch pipe through which thepilot flame burns is at the end of the expansion tube there is somelikelihood of the pilot flame becoming extinguished due to soot formingin the pipe, and there is thus considerable danger of explosion. It isthe object of my 135 discharge pipe that the danger ofclogging up andthus causing the pilot flame to become extinguished will beminimized.

i he above and other objects to which ref: erence will be made in theensuing disclosure I accomplish by that certain combination andarrangement of parts of which I have shown a preferred embodiment. 7Referring to the drawings Figure 1 is a plan View of the preferred typeof pilot. I Figure 2 is a side elevation of the plot.

-Within the shell 1, having a cut-away portion 2 at the end thereof,whichextends into the furnace, there is'a tubular expansion pipeinvention therefore to so construct the branch possibilityofthe pilot 7j tinguished,and whi'le broadly the idea of-the thermostatic control isold, itis my thought i that' I'ThaVeQadided*thereto asafety featurewhichiwillfgreatlypromote the use of this 7 I 3 secured to the shell asindicatedjat 4. l The tube is thus fixed at its outjerend'. The innerend passes through the open end of the shell and hasa slot 5' thereininto which'the gas to be supplied flows from an orifice 6 in the 1 gassupply pipe 7.--'The tube has a piston 8 securedto its end whichoperates a switch 9 and thus, through an electric control valve (notshown), the flow of gasto the pilot is governed. Extending atsubstantiallya right angle from the end of the tube'thereis a branchpipe 10' through which gas may pass to the end ll of the branch thuscausing the pilot flame. In'addition to the main branch pipe '65 C' 10there is a supplemental gaspipe 12 extending from a'positio'nin-the gasexpansion tube towardthe inner of a row of expansion tubeflame orificesl3'and joiningthe pipe 10 at 12a! The pipe'12 is provided with a slot '714 which extendsfrorn the' endof the *di's' charge opening-I1 along theside ofthepipe 12 until it bisectsthe tube 3 at l5 interme J diatetherow of expansion tube orifices 13. f

' The operation of the pilot as follows} :2 ,The shell ektendshorizontally into the furnacei From the orifices 13 a series of smalljets offfia'me cause the expansion tubefto heat up and expand causingthe operation of;

Gas will flow out theelectricfswitch' 9." V v through the slot 14 assoon as there is enough to more than supply gas forthe orifices 13and'the pilot fiame issuing from the. end ll 'of the tubefwilbalwaysbeignited due to thecontinuous; flame. extending along the! 85.1

slot 14., i The gas fiojwing 'from the slot 14 will alwaystbe igniteddue to the qopening. v '15 which willgalways be ignited by the flamesissuing-r froinflthe orifices}. 13.1 Shouldgthef pipe ,10 become blockedup due toi-jsootthere; I

supplemental pipe 12.

willfalways be ia free fiow- 'o f gas through the Thusl provide a pilotminimizes the flamebecomiiig 'QXI- ample of my invention, I includetherein such changes in the positioning of the main and supplementalbranch pipes as will occur to one skilled in the art and I consider suchmechanical modifications within the scope of my invention.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is V 1. A gas pilot comprising a shell havingan expansion tube mounted within the shell and having an end of the tubefixed to a cutaway portion of the shell, said tube having a series oforifices extending along the tube in an exposed portion of the uppersurface of the tube adjacent the end thereof, a branch pipe extending atan angle from the fixed end of the tube, and a supplemental pipeextending across from the tube adjacent the orifices therein to saidbranch pipe.

2. A gas pilot comprising a shell having an expansion tube mountedwithin the shell and having an end of the tube fixed to a cutawayportion of the shell, said tube having a series of orifices extendingalong the tube in an exposed portion of the upper surface of, the tubeadjacent the end thereof, a branch pipe extending at an angle from thefixed end of the tube, and a supplemental pipe extending across from thetube adjacent the orifices therein to said branch pipe, said tube havinga slot extending through the side thereof.

3. A gas pilot comprising a shell having an expansion tube mountedWithin the shell and having an end of the tube fixed to a cutawayportion of the shell, said tube having a series of orifices extendingalong the tube in an exposed portion of the upper surface of the tubeadjacent the end thereof, a branch pipe extending at an angle from thefixed end of the tube, and a supplemental pipe extending across from thetube adjacent the orifices therein to said branch pipe, said tube havinga slot extending through the side thereof, and said slot bisecting the.upper surface of the tube.

4. In a device of the character specified, a shell containing athermostatic expansion tube through which gas flows to a pilotdischarge, a branch pipe extending from a fixed end of the tube at anangle to thetube, the end of said pipe comprising a discharge for thepilot flame, and an auxiliary pipe extending from the tube across tosaid branch pipe.

5. In a device of the character specified, a shell containingathermostatic expansion tube through which gas flows to a pilotdischarge, a branch pipe extending from a fixed end of the tube at anangle to the tube, the end of said pipe comprising'a discharge for thepilot flame, and an auxiliary pipe extending from the tube across tosaid branch pipe, said auxiliary pipe having orifices extending throughthe side wall thereof, for the purposes described.

6. In combination in a gas pilot, a shell having an expansion tubetherein provided with a series of orifices extending along the tubeadjacent the end thereof, a discharge port for the pilot flame, and abranch pipe leading from the tube intermediate the orifices to saiddischarge port.

7. In combination in a gas pilot, a shell having an expansion tubetherein provided with a series of orifices extending along the tubeadjacent the end thereof, a discharge port for the pilot flame, and abranch pipe leading from the tube intermediate the orifices to saiddischarge port, said branch pipe having discharging means extending froma side wall whereby a feeding flame from the orifices to the dischargeport is provided.

8. In combination in a gas pilot, a shell having an expansion tubetherein provided with a series of orifices extending along the tubeadjacent the end thereof, a discharge port for the pilot flame, and abranch. pipe leading from the tube intermediate the orifices to saiddischarge port, said branch pipe having discharging means extending froma side wall whereby a feeding flame from the orifices to the dischargeport is provided, said discharging means arranged at such a level insaid pipe as to receive a supply of gas not consumed in said orifices.

OTTO H. RODENBERG.

